House Energy Rating
A House Energy Rating is an index of a building's thermal performance (i.e. heating and cooling requirements) for residential homes in Australia. The Australian Building Codes Board introduced energy efficiency measures for houses into the Building Code of Australia (BCA) on 1 January 2003. It has been adopted by all Australian states and territories which did not already have an equivalent system in place. Victoria and South Australia have gone beyond the standard, and mandated, instead of 4-stars, a 5-star rating (enacted July 2004) - all new homes and apartments built in Victoria must comply with the 5 Star standard. This means it is compulsory for new houses to have: * 5 Star energy rating for the building fabric, and * A rainwater tank for toilet flushing or a solar hot water system, and * Water efficient shower heads and tapware. During 2006, requirements for 5-star energy ratings were introduced for new homes through the BCA in Western Australia and the Australian Capital Territory. As of mid 2007 Tasmania, Queensland and the Northern Territory have not adopted 5 star requirements for new homes. New South Wales has not adopted requirements under the BCA and operates its own Building Sustainability Index or BASIX. Victorian consumers and building practitioners can find out more about the 5-Star energy ratings by visiting Make Your Home Green – Building Commission History The Five Star Design Rating (FSDR) was an award developed in the 1980s for "high efficiency through excellence in design and construction" which assisted builders in marketing energy efficient home designs. The certification was developed by the Glass, Mass and Insulation Council of Australia (GMI Council) together with CSIRO Division of Building Research. The GMI Council was funded by Federal and State governments (NSW, SA, Tasmania, Victoria) and by private investors.Energy Efficient Building Design, Resource Book. 1992. Holger Willrath. Brisbane Institute of TAFE. Unit 1. Under FSDR, the basic elements of glass, mass and insulation were the basis of the design principles of a five star home.Ballinger, J. A. (1998). The Nationwide House Energy Rating Scheme for Australia (BDP Environment Design Guide No.DES 22). Canberra: The Royal Australian Institute of Architects.. The building industry did not widely accept the system due to its simple pass/fail rating and its restrictive guidelines.Development of a new framework for a House Rating Scheme (HRS) Maria Kordjamshidi. August 1997. University of New South Wales. http://www.library.unsw.edu.au/~thesis/adt-NUN/uploads/approved/adt-NUN20071003.110139/public/ In the 1990s, individual states developed their own schemes. The Victorian scheme, based on a computer program, was eventually accepted as the most effective. However, it worked poorly in warm humid climates such as found in Queensland. The development of a nationwide House Energy Rating Scheme (NatHERS) began in 1993, based on the Victorian scheme, using the CHEETAH / CHEENATH engine developed at CSIRO. Software products NatHERS, FirstRate and Quick Rate, BERS, Q Rate and ACTHERS are based on this engine. NatHERS and BERS run the engine directly, while others use correlations based on the engine. 6-Star rating A 6-Star rating indicates that a building achieves a very high level of thermal energy performance. Houses in the suburb of Aurora, Victoria in Melbourne will have an energy efficiency rating of at least 6 stars. 5-Star rating , by star rating. See image page for details.]] A 5-Star rating indicates that a building achieves a high level of thermal energy performance, and will require minimum levels of heating and cooling to be comfortable in winter and summer. Houses which achieve a 5 star rating, compared to the average 2 star home , should be more comfortable to live in, have lower energy bills, and costs to install heating and cooling equipment should also be lower. Energy assessments take into account different climatic conditions in different parts of the country and are benchmarked according to average household energy consumption particular to a given climatic region. The house energy rating does not currently include the efficiency of any appliances fitted or used within the house. There are also no physical testing requirements, so air tightness testing is not required as it is with the regulations in the UK. Software One of the best ways to achieve an energy rating on a proposed house is by using House Energy Rating Software (HERS). This kind of software will simulate a home and provide estimates for the energy needed to heat and cool that home over the course of the year. The Nationwide House Energy Rating Scheme (NatHERS) is a framework by which this kind of software is assessed, compared and accredited for use in Australia. The First Generation of accreditation included the FirstRate 4, BERS 3.2 and NatHERS software packages, allowing accredited assessor to use this software to provide energy ratings. The Second Generation of accreditation was tightened and improved, meaning that software had to become more precise, accurate and powerful in response. The Second Generation of software must take into account more features and realistically model elements such as natural ventilation, the cooling effects of ceiling fans, under-floor heating and the effects of attached dwellings such as apartments. The First Generation is being phased out for the Second Generation of software to takeover. In Victoria, the First Generation of software will no longer be acceptable for energy ratings after the 30th of April, 2009. This means that First Rate 4, NatHERS and so on will no longer be valid energy rating tools for new Victorian homes. FirstRate is the software package developed by Sustainability Victoria. Over the course of 2008, Sustainability Victoria has produced a new version, FirstRate 5. FirstRate 5 received provisional Second Generation accreditation on 31 August, 2007. This means that it can be used for house energy ratings now. From May 2009, it will be the only version of FirstRate accredited for use in Victoria. FirstRate Five uses the AccuRate calculation engine with a graphic interface. It includes: the ability to zone the house according to how each room will be used, the ability to rate up to 10 stars and the full range of AccuRate climate zones (69 in Australia). Other Second Generation software acceptable for use in Victoria now and after the 30th April deadline includes BERS Professional and AccuRate. AccuRate shares a calcuation engine with FirstRate 5 but has a more complete data input method which allows for more precise energy ratings but lacks FirstRate5's graphic interface. Each software package will be appropriate in different circumstances.http://www.nathers.gov.au/ Controversies *The rating system does not consider factors such as sustainable materials, electricity sources, waste treatment and transportation to, from and within urban environments. *There are a number of ways the user of the FirstRate software can cheat the program to achieve higher star ratings. Many such techniques have been learned by TAFE students as they learn the program. It is not difficult to learn and requires only selecting particular variables whose values are inherently inaccurate. *Keeping the above in mind, some elements such as draught strips, insulation, etc. can be selected in FirstRate but may never be included in the final drawings. In many cases, builders do not install particular systems properly. This, combined with many other factors, means that the completed building can sometimes have a rating of up to 3 stars different from its initial rating. *The legislation was passed before there was actually a method to rate the buildings, and the software was rush released and as a result is inaccurate and inappropriate. *The ratings were seen as a quick short-term answer to a problem that the government at the time had to deal with and as a result, no long term solution exists and the problem itself remains mostly unsolved. *Large companies such as Simmonds, AV Jennings, etc., have been accused of cheating the rating system to achieve higher stars to market their pre-built product homes as more environmentally friendly. *The rating system does not deal with many of the problems inherent in low-density urban environments. *FirstRate and the Green Star system has been the subject matter of a prolific running joke within the building industry within Metropolitan Melbourne since its creation, and has become synonymous with government inaction and short-sightedness in the industry. *Many explain that the anti-progressive nature of Australia's building industry requires tough action and long-term solutions when dealing with issues of sustainability to counter ingrained attitudes. State Government initiatives *ACT House Energy Rating Scheme (ACTHERS) http://www.actpla.act.gov.au/design-guide/acthers/, requires new or previously lived in residential homes to have an Energy Efficiency Rating (EER) Statement, prepared by an accredited ACTHERS assessor, if they are to be sold. As of the February 2006, the required software used in assessment is FirstRate, Version 3.1 or Version 4. http://www.actpla.act.gov.au/design-guide/acthers/eer_sell.htm *In Victoria all new homes built since 2005 are required to achieve a 5 Star rating . Rating can be performed using any software approved by NatHERS. * In South Australia, all new homes (and alterations to existing homes) are required to achieve a 5 star rating. This requirement was introduced on 1 May 2006. * Western Australia: in 2007 the WA Government introduced further energy and water usage regulatory requirements. 5 Star Plus consists of two codes: the Energy Use in Houses Code, which requires a minimum standard of energy performance for a hot water system; and the Water Use in Houses Code, which includes provisions for alternative water supplies, efficient fixtures and fittings, and grey water diversion. * In Queensland it is proposed that from either the 1st January 2009, or when the Building Code of Australia 2009 update is released in May 2009, that all new homes built in Queensland will be required to achieve a 5 star energy equivalent rating. Currently the minimum requirement is 3.5 stars. References * http://qld.hia.com.au/documents/2010/6%20Star%20Implementation%20newsflash.pdf In Queensland, 6 Stars have had to be achieved from 1 May 2010. See also *BASIX, NSW Government's Building Sustainability Index http://www.basix.nsw.gov.au/ *Energy conservation *EnerGuide for Houses (Canada) *Home energy rating (United States) *National Home Energy Rating (UK) *Environmental economics *Green building *Zero-energy building *Low-energy house *Passive house Category:Low-energy building Category:Energy conservation Category:Energy in Australia